Hardware failure is the leading cause of data loss; so ignoring hardware failure is the fastest shortcut to losing data. Because you don’t want to lose your data, do not ignore the hardware failure and backup your systems and data.

If you use tape as your backup medium, you could alsolose your data. With the high failure rates associated with tape, sooner or later you’re assured that you’re going to need to recover your data and not be able to do so.

SAN or NAS storage devices as the source of the backup and the target of a backup is another highly probable way to losing data. We are not referring to snapshots in between physical transfers of data off the SAN or NAS; we are talking about using your SAN and NAS for primary storage and for backup storage exclusively.

What to do instead

To protect yourself from hardware failure, you have to move your data from primary storage to a completely separate secondary storage. That secondary storage can and should be less expensive than your primary storage, but it has to have RAS (Reliability, Availability, Serviceability) characteristics that are as good or better than your primary storage.

Those requirements rule out tape as well as ruling out partitioned primary storage (SAN or NAS) – although SAN and NAS snapshotting may be used between primary backup protection. The best approach is some type of D2D (Disk-to-Disk) backup. The advantage to D2D backup is that you are using secondary media with higher reliability characteristics than tape while still insuring that you have a physically separate secondary storage set so that you can survive hardware and system failure.